Stretchable fabric switch

ABSTRACT

The present invention provides a stretchable fabric that may serve as a switch device or coupling to an electronic device and a power source by merely stretching or pushing the fabric. The stretchable fabrics may be usable in a wearable garment, furniture, or other suitable locations where it can be incorporated to close a circuit. Through a releasable stretching or pushing action by the user, electrically conductive strips integrated in the fabrics come in contact to activate related ancillary equipment such as power supplies or electronic devices.

The present invention relates to a fabric switch system intended topermit the connection of an electronic device or power source. Morespecifically, the present invention relates to a stretchable fabricswitch system that may be incorporated into a garment, furniture, or ina location most conveniently accessible to the user to serve as acoupling of electrical signals or power.

Intuitive switches that utilize soft fabric materials are conductivefibers and are highly desirable in wearable or other electronicsapplications. Techniques known for providing an electrical switch systemin clothing fabric typically include adding electric wires and controldevices that are standard “off the shelf” electronic components to thefabric, by incorporating the wires directly into the fabric or byattaching the wires to the fabric, e.g., by sewing.

The present invention relates to a stretchable switch system that can berealized in a simple, intuitive, and reliable implementation. Inparticular, the present invention facilitates manufacture of such switchsystems as close as possible to the manufacturing techniques used in thegarment industry for widespread acceptance within the garmentmanufacturing industry.

The present invention discloses stretchable electro-conductive fabrics,which include an inner cord comprising at least two conductive cordsreleasably connected in series and a non-conductive cord enclosing theinner cord. The non-conductive cord is stretchable when pulled torelease the contact between the two conductive cords that are in contactelectrically, thus opening a circuit. This “pull to break” action canoperate a simple electronic functionality and can be manufactured usingconventional textile manufacturing processes. In the embodiment, bothends of the inner cord may be coupled to a fabric circuit integrated ina garment or furniture, or they can serve as a coupling to an electronicdevice or a power source.

According to one aspect of the invention, a garment or furniture ofdesired form and function can be constructed in a conventional mannerusing readily available fabrics and materials, and the stretchableelectro-conductive fabrics serving as a switch system can be positionedadvantageously within a wearable garment or furniture that permits easymanual activation by a person. This type of switch could haveapplication on surfaces that can have switching created by stretching ofthe fabrics, i.e., clothing, seating, and fabric products.

According to another aspect of the invention, a fabric switch includinga matrix of woven fibers that are non-conductive and a pair ofconductive fibers interwoven in the woven fibers are provided to form anelectrical circuit. In operation, the conductive fibers come in contactelectrically when said woven fibers are in a relaxed mode but come apartin a stretch mode.

FIG. 1 a illustrates a first embodiment of a stretchable fabric switchsystem in accordance with this invention.

FIG. 1 b illustrates the switch system of FIG. 1 a when stretched inaccordance with a first embodiment of this invention.

FIG. 2 a illustrates a second embodiment of a stretchable fabric switchsystem in accordance with this invention.

FIG. 2 b illustrates the switch system of FIG. 2 a when stretched inaccordance with a second embodiment of this invention.

In the following description, for purposes of explanation rather thanlimitation, specific details are set forth such as the particulararchitecture, interfaces, techniques, etc., in order to provide athorough understanding of the present invention. For purposes ofsimplicity and clarity, detailed descriptions of well-known devices,circuits, and methods are omitted so as not to obscure the descriptionof the present invention with unnecessary detail.

Referring to FIG. 1 a, a fabric system 10 according to an embodiment ofthe present invention includes a conductive inner cord 12 surrounded bya stretchable hollow cord 14.

The conductive inner cord 12 running through the stretchable hollow cord14 is broken in different lengths and releasably connected together inseries depending on the mode of operation. In particular, the conductiveinner cord 12 is woven of a conductive non-stretch yard, which isseparated in at least one place when pulled. The hollow cord 14 may bemade water-resistant or water-proof in the area surrounding theconductive inner cord 12 to provide additional protection.

The material of the stretchable hollow cord 14 may be either natural orsynthetic, and the fabric created from such materials can be eitherwoven or sheet-formed in any well-known manner. Alternatively, thestretchable hollow cord 14 may be constructed from non-woven (felted) orknitted fabrics or a composite structure. However, in each alternativecase, an electrically conductive inner cord 12 is included in theproduction of the fabric, thus providing electrically conductivecapabilities.

In the embodiment illustrated in FIG. 1 a, the cords 12 and 14 may beincorporated in a garment 16, such as a conventional sleeveless topshirt or a short or long-sleeved vest or jacket, or furniture to serveas a coupling of electrical signals or power. In addition, theconductive cord 12 may be coupled to a power source, an output device,fabric-mounted circuit, etc., in the form of loops to receive orotherwise engage equipment considered ancillary to the fabric switch 10,such as an external heart-monitoring device, external defibrillator,cell phone, radio, pager, GPS device, personal communication assistant,or other signal transmitter or duplex interactive system. Alternatively,such ancillary equipment or other electronic devices may be integratedin the garment or furniture and used in conjunction with the fabricswitch system 10 for transmitting the desired signals or power in anywell-known manner.

Referring to FIG. 1 a, when the cords 12 and 14 are in their relaxedmode, the segmented pieces of the conductive inner cords 12 a-12 n arein contact physically and electrically with each other in series, thusclosing a circuit. Referring to FIG. 1 b, when the cord 14 is stretched,as indicated by arrow, the different pieces of the inner conductive cord12 separate and therefore break the circuit. The circuit returns toclose when the force is released. Therefore, a user can readily engagethe opening and closing of a circuit by merely pulling the cord 14.

Referring to FIG. 2 a, a fabric switch system 30 according to anotherembodiment of the present invention includes a matrix of anon-conductive knit structure 20 and a pair of conductive threads orfibers 22 and 24 interwoven in the knit structure 20 and come in contactelectrically with each another during a relaxed state. The conductivefibers 22 and 24 serve as electrical conduits capable of carrying datasignals and/or power in any known manner, and may be connected toelectrical devices soldered directly onto the fabric. Alternatively, theconductive fibers 22 and 24 may be connected to a fabric-mounted circuitor electrical components in the form of loops to receive or otherwiseengage equipment considered ancillary to the fabric switch 10, such asan external heart-monitoring device, external defibrillator, cell phone,radio, pager, GPS device, personal communication assistant, or othersignal transmitter or duplex interactive system.

Referring to FIG. 2 a, in a relaxed state, the conductive fibers 22 and24 make contact with each other physically and electrically, thusclosing a circuit. Referring to FIG. 2 b, when the fabric structure 20is stretched or pushed, the conductive connections between theconductive fibers 22 and 24 split from each other, and hence the circuitis open. Accordingly, a user can readily engage the opening and closingof a circuit defined by the two conductive fibers 22 and 24 or anancillary device by merely stretching or pushing the fabric layers.

While the preferred embodiments of the present invention have beenillustrated and described, it will be understood by those skilled in theart that various changes and modifications can be made, and equivalentsmay be substituted for elements thereof without departing from the truescope of the present invention. Thus, the shape of an interconnectsystem in the drawings should not impose limitations on the scope of theinvention. Therefore, it is intended that the present invention not belimited to the particular embodiment disclosed as the best modecontemplated for carrying out the present invention, but that thepresent invention include all embodiments falling within the scope ofthe appended claims.

1. A fabric switch comprising: an inner cord (12) including at least twoconductive cords (12 a-12 n) releasably connected in series; and anon-conductive cord (14) enclosing said inner cord (12), wherein saidnon-conductive cord (14) is stretchable to release the contact betweensaid at least two conductive cords (12 a-12 n) electrically.
 2. Theswitch of claim 1, wherein the material of said non-conductive cord (14)defines a moisture-resistant enclosure for said inner cord (12).
 3. Theswitch of claim 1, wherein said inner cord (12) and said non-conductivecord (14) are shaped in a loop form.
 4. The switch of claim 1, whereinsaid inner cord (12) is coupled to a fabric circuit integrated in agarment.
 5. The switch of claim 1, wherein said inner cord (12) servesas a coupling to an electronic device.
 6. The switch of claim 1, whereinsaid inner cord (12) serves as a coupling to a power source.
 7. Theswitch of claim 1, wherein said inner cord (12) engages and supportsancillary units to transmit electronic signals.
 8. The switch of claim1, wherein said inner cord (12) is coupled to a fabric circuitintegrated in furniture.
 9. A fabric switch comprising: a matrix ofwoven fibers (20), said woven fibers (20) being electricallynon-conductive; a pair of conductive fibers (22,24) interwoven in saidwoven fibers (20) so as to form an electrical circuit; and, wherein saidconductive fibers (22,24) come in contact electrically when said wovenfibers (20) are in a relaxed mode and come apart in a stretch mode. 10.The switch of claim 9, wherein said conductive fibers (22,24) arecoupled to a fabric circuit integrated in a garment.
 11. The switch ofclaim 9, wherein said conductive fibers (22,24) serve as a coupling toan electronic device.
 12. The switch of claim 9, wherein said conductivefibers (22,24) serve as a coupling to a power source.
 13. The switch ofclaim 9, wherein said conductive fibers (22,24) engage and supportancillary units to transmit electronic signals.
 14. The switch of claim9, wherein said conductive fibers (22,24) are coupled to a fabriccircuit integrated in furniture.
 15. A method for permitting a person toactivate a switch, said method comprising the steps of: providing aninner cord (12) including at least two conductive cords (12 a-12 n)releasably connected in series and a non-conductive cord (14) enclosingsaid inner cord; mounting both said inner cord (12) and saidnon-conductive cords 14) to a garment or furniture; and, stretching saidnon-conductive cord (14) to release the contact between said at leasttwo conductive cords (12 a-12 n).
 16. The method of claim 15, furthercomprising the step of protecting said inner cord (12) from ambientconditions by enclosing it in said non-conductive cord (14) having amoisture-resistant material.
 17. A method for permitting a person toactivate a switch, said method comprising the steps of: providing amatrix of non-conductive woven fibers (20) and a pair of conductivefibers (22,24) interwoven in said woven fibers (20) so as to form anelectrical circuit; mounting both said woven fibers (20) and conductivefibers (22,24) to a garment or furniture; and, selectively stretchingsaid woven fibers (20) so that said conductive fibers (22,24) come incontact electrically when said woven fibers (20) are in a relaxed modeand come apart in a stretch mode.